code: def _get_mustc_item(self, idx):
      file_path, offset, duration = self.wav_list[idx]
      waveform, sr = torchaudio.load(
          file_path, frame_offset=offset, num_frames=duration
      )
      assert sr == SAMPLE_RATE
      transcript = self.trans_list[idx].replace("\n", "")
      return (waveform, transcript)
  
file_path: audio/examples/asr/emformer_rnnt/mustc/dataset.py
imports: from pathlib import Path
  from typing import Union
  import torch
  import torchaudio
  import yaml
label_desc: Use image node_id 2 for calling the MUSTC obj's underlying member method code with example usage: obj._get_mustc_item(idx) and returns: waveform,  transcript